Electronics > Projects, Designs, and Technical Stuff
INA193 High side current sensing, ground problem?
Atom:
--- Quote from: namster on August 15, 2019, 05:05:07 pm ---for low cost regulation you can use a zener diode , by choosing the right value of R3 , in previous post i connected the régulator before the shunt resistor that was error on my part , the INA193 brunout beaucoup of high supply voltage ! not because you connect the ground together .
for more viable version you can replace your adc with another wich have separate ground ( Analog and Digital ) .
--- End quote ---
i pushed the ina at max 40V and it burned WITH the ground in common.. now ill try to push it to 70V without the common ground and see if something happens.
i dont mind purchasing an external and isolated psu fot the ina. i could also wound additional spires on a toroidal transformer and have a lot of isolated outputs(thats what i'v planned to do)
i could replace the adc but this one is really cheap at about 1 euro and its a 15bit one ..thats really good for the price
the ina does not burn out from the high voltage, it has a separated power supply @5V
namster:
this kind of IC have to be connected with one ground for correct operation (supply and Vin ) , i think that you have to review your design.
the tooridal transformer isn't a good idea , in a DC voltage the transformer will be saturated .
Marco:
--- Quote from: Atom on August 15, 2019, 08:27:45 pm ---any help is appreciated
--- End quote ---
It would probably help if you admitted to yourself that you're almost certainly doing something wrong and one of the myriad assumptions you are making is wildly flawed. If you blew up the INA193 you either have far more voltage on the supply leads, input or even output than you think you have.
Jeroen3:
--- Quote from: Atom on August 15, 2019, 08:27:45 pm ---when connecting the 2 grounds togheter i get huge currents passing trough the "common ground lead"... from 500ma to even 1A, the readings from the ina gets all wrong and the voltage VCC gets pulled up to 5 V
--- End quote ---
Didn't you notice the amount of current flowing is equal to the current limit set on your delta power supply?
Power the INA supply from a 9V battery, see what happens.
Atom:
problem solved.
while soldering a ground cable on the pcb the insulation melted ..melted the isulation of another cable..one of the 2 from the sense lines of the shunt... so the 2 cables where touching..
here's testing at 50V 2.4A
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